sunxi: Add Sinlinx SinA33 defconfig

Sinlinx SinA33 is a core/daughter board SDK kit from Sinlinx. It has
the A33 SoC, USB host, USB OTG, audio input/output, LCD, camera, SDIO
and GPIO headers.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>